Black Diamond

County:: King County
County Seat:: No
Area (mi²):: 6.598
State:: Washington

Black Diamond is a city located in King County, Washington. Black Diamond has a 2025 population of 7,772. Black Diamond is currently growing at a rate of 8.14% annually and its population has increased by 60.38% since the most recent census, which recorded a population of 4,846 in 2020.

The average household income in Black Diamond is $172,884 with a poverty rate of 1.14%. The median age in Black Diamond is 38.1 years: 39.9 years for males, and 36.6 years for females.

Demographics

The racial composition of Black Diamond includes 74.66% White, 11.39% Asian, and smaller percentages for other race, Black or African American, Native American, Native Hawaiian or Pacific Islander and multiracial populations.

Population by Race

White

Asian

Two or more races

Other race

Black or African American

Native American

Native Hawaiian or Pacific Islander

Race	Population	Percentage (of total)
White	4,239	74.66%
Asian	647	11.39%
Two or more races	620	10.92%
Other race	151	2.66%
Black or African American	21	0.37%
Native American	0	0%
Native Hawaiian or Pacific Islander	0	0%

Black Diamond Marital Status

Married

Widowed

Divorced

Separated

Never Married

Economics and Income Statistics

Black Diamond's average per capita income is $86,221. Household income levels show a median of $144,728. The poverty rate stands at 1.14%.

Families: A family includes the owner or renter of the home along with everyone related to them - whether through birth, marriage, or adoption. This includes relatives like spouses, children, parents, siblings, grandparents, and any other family members.

Households: A household includes all the people who occupy a housing unit (such as a house or apartment) as their usual place of residence.

Non Families: A nonfamily household is either someone living alone or when the owner/renter lives with people they aren't related to, like roommates.

Name	Median	Mean
Married Families	$165,855	-
Families	$155,000	$184,640
Households	$144,728	$172,884
Non Families	$86,050	$130,828

$86,221

Average Income

$144,728

Median Household Income

1.14%

Poverty Rate